【作者】 王胡成；

【导师】 陈山枝；

【作者基本信息】 北京邮电大学 ， 计算机科学与技术， 2008， 硕士

【摘要】 多协议标签交换MPLS(Multi-Protocol Label Switched)技术日益成为新一代骨干网络中的关键技术,而互联网的骨干网络是关系国计民生的重要战略资源,网络设施发生的故障或损毁,都会在不同程度上对生产和生活产生负面影响,特别是在非常时期或特殊环境下,如战争、大规模自然灾害等极端环境下,因此提高网络的自愈能力以及生存能力尤为重要,为此,迫切需要在MPLS网络中添加OAM机制。OAM机制是现代网络管理中的一个重要概念,它能够提高网络可靠性,简化操作,降低网络运行成本,为网络服务质量提供保障。MPLS网络中的OAM机制能为MPLS网络中的业务运行提供保障,因此,该OAM机制也一直是国内外研究的热点之一。本论文对现有MPLS OAM技术以及相关的标准规范进行研究和分析,分别对快速故障检测机制和快速故障恢复机制进行深入的研究,提出两种基于MPLS层的故障探测方法——简单LSP探测机制和双向FFD机制,和一种基于链路层的故障检测方法——网卡对物理连接的监测机制;同时提出一种简单的快速故障恢复方案——LSP保护倒换机制。简单LSP探测机制和双向FFD机制均基于我们自行设计实现的OAM内核支持模块,该模块能够处理自定义的特殊的OAM分组来进行链路探测,同时在实现跨层设计,绕开复杂的TCP/IP协议栈的处理,直接将数据包通过MPLS socket接口送入MPLS层处理,并使用OAM标签来在MPLS层区别处理此类探测包。网卡对物理连接的监测机制完成对物理连接状态变化的自动告警。在快速保护倒换机制中,我们通过MPLS netlink接口修改MPLS转发表的信息,完成对LSP的切换。最后通过实验来测试了这些故障检测机制或故障恢复机制的性能并做出了分析。更多还原

【Abstract】 MPLS(Multi-Protocol Label Switched) is increasingly becoming the key technology in next generation backbone network, the backbone network of internet is the important resource which care about the national economy and the people’s livelihood, the failures or the ruin of network structure more or less have a bad impact on the production and livelihood in sociaty, especially in unusually period or extremely evironment, such as war, natural calamities and so on. So, it is very important to improve the ability of self-healing and surviving of network, for this, OAM function should be add into the MPLS network. 0AM fuction is a important conception in modern administration of network, it can improve the reliability of network, make the operation simple, reduce the operating cost of network and guarantee the quality of service in network. The OAM mechanism in the MPLS network can guarantee the service operation nomally, so it is the hot research points all time in the world.This papar researched and analyzed recent technology, standards and criterions about MPLS OAM, especailly in fast failures detection mechanism and failures recovery mechanism, which are deeply researched in the paper, then we put forward two kinds method of failures detection mechanism in MPLS layer - the mechanism of LSP detection and the mechanism of bidirection FFD, and a method of failures detection mechanism in link layer - the mechanism of physical link monitoring; we also put forward a simple method of fast failures recovery - LSP Protected switching mechanism. Both of LSP detection mechanism and bidirection FFD mechanism are base on the module of MPLS OAM which we designed and realized by ourself, this module can use the OAM packets , which defined by ourself, to detect the link failures, and avoid the complex process in TCP/IP protocol stack, realize the cross-layer design, which can send the data packets to MPLS layer directly by MPLS socket interface. The mechanism of physical link monitoring can raise the alarm when the status of physical link change. In fast protected swithing mechanism, we modify the information of MPLS forwarding table by MPLS netlink interface, to realize swithing among LSPs. At last, we made some experiments to test and analyze the performance of these failure detection mechanism and failure recovery mechanism.更多还原